Answer Happy

Please help, this is my third time attempting this a question like this and I keep getting it wrong. I used the c/(1+I)^k but still didn't work. Please show me from step to step. Thank you
Consider the following two tractors a company can purchase. The following tables provide the costs the company will incur (in thousands of dollars) in the lifetime of each tractor. Diesel Gasoline Initial Cost $18,000 $6,000 Find the present value of the costs of using the two tractors. Diesel Number T Operating Costs per Year $10,000 $12,000 The transportation firm can only afford one of the tractors. The two tractors have identical production capabilities. The firm's cost of capital is 10%. Gasoline= Number Expected Life 5